Thomas c



@eine taire @anni l @Hirn THOMAS c. BALL, oraaLLows FALLS, vnaMorrr, `Asslel'voa 'To HIM'- sELF, ABIJAH s. CLARK, AND SUMNER CHAPMAN, orsAME PLACE. l

Letters Patent No. 71,678, dated December 3, 1867. I

IMPROVEMENT IN HEAD-BLOCKS FOB. SAW-MILLS.

TQ AIiL WIIOM IT MAY CONCERN:

I Be it known that I, THOMAS C. BALL, ofBellows Falls, in thc county of Windham, and 'State of Vermont,

have invented a new andimproved Mill-Set; and IA do hereby declare. the following to be a full, clear, and

exact description of the same, reference being had to the accompanying drawings, forming part of this specification, and in which- Figure l is a top view of my.invention.

Figure 2 is aside elevation of the same.

Figure 3 is a side view of the wheel S', showing the operation of the reversing-apparatus.

Similar letters of reference indicate corresponding parts in the several figures.

In this invention, which is designed for circular-saw mills, a table slides back and forth under the headblock, having a rail vattached to its' upper surface, which slides between two pins projecting downward from the knee. The rail, being inclined at an angle of thirty or forty degrees from the perpendicular to the head-block, causes the knees to advance or recede, as the table moves in one direction or theother. Several of these tables are connected by a rod, which is operated by a novel reversing-arrangement.

In order that others skilled in the art to which my invention appertains may be enabled to make and luse the same, I will proceed to'describe it in detail. l i y In the drawings, A A are the carriage, B the head-block, and C C the knees of a circular-saw mill. Underl each head-block is a triangular table, T, which slides back and forth-in a suitable horizontal bed. These tables areconnected together by a rod, R, running the whole length'of the carriage, which rod, being operated by a vertical shaft, S, pinion, I, and rack, r, moves all the tables through at the same instant. Guide-pieces, au, attached to 'the tables, and operating in connection with corresponding pieces, 'u' 11', attached to the carriage or head-blocks, steady and direct the motion of the tables.' Along the upper surface of each table extends a rail or cleat, D, in a direction obliquely across the space between the sides of the carriage. The walls of the rail are yertical and smooth, and the rail itself is fastened firmly to tlie'tablc. Lugs or pins, d 0l, project downward from the knees C C through a slot in the head-block B,`one on each sideof the rail D, and fitting accurately,

but not tightly, to the sides of the rail. The rails on the lseveral tablesof a carriage are made parallel tok cach other.

It is evident from the description above that when the 'rod Ris advancedor retracted, the rails D D, sliding' between the lugs d d, will move the knees backward or forward on the head-blocks precisely at the same instant und through the same distance, and that when the rod is motionless the-rails will hold theqknees rmly in their place. And it is further evident that by adjusting the machine to move the rail back or forth to any required distance at cachent of the saw, a mill-set will be provided which will work without cogs or gear of any description, and with the greatest precision and accuracy.

The following arrangement constitutes my apparatus for advancing or reti-acting the rod R to any required distance at each eut ofthe saw: I attach to the vertical shaft S, which works the rod R, a stout 4wheel or drum, AS", around the periphery of which is a'deep, square groove, s. Above this wheel is a stout ring, W, attached to the post If', which supports the bearings of the shaft S, and provided with a sliding gauge, w, adjustable at anypoint on the ring by means of a set-screw. Between the ring W and wheel S is a stout horizontal-acting reversing-1ever,-L, pivoted on theA shaft S, and providedwith an upright pin, Z, which strikes against the gauge I w, and arrests the motion of the lever in that direction, the lever itself striking against a pimp, projecting froxmthe post P', which arrests the motion of the lever in the opposite direction. Thus the distance through which the lever travels can, by adjusting the gauge at dierentdistances from the piu p, be regulated with perfect accuracy; and as thelever turns the shafts, the means which regulates the distance travelled by the lever regulates also the distance travelled bythe rodrR, and the thickness of the saw-cut.- Y.

It remains to describe thc means by which the lever operate the wheel S and shaft S. In the groove s works a small at plate, a, attached to a swinging arm, a', which is pivoted on the lever and hangs beneath it. When the arm a is swung in either direction, a few degrees from a vertical position, theplate a cramps in the groove s, and prevents the arm from moving any farther in that direction- A heavily-weighted lever, M, is pvotcd cn 'mais the yrcversnglever L, alongside of the arm a', and is provided with. jaws, zz, on its short arm, which operate against a' pin, e, projecting from the back of the arm a. When the long weighted -arm of the lever M is in a vertical position, the jaws z'z' are at equal distances from the pin e, and the arm a', by its own weight, assumes a vertical position. If the weighted arm of lever M be inclined to the right, the jaw z', on that side, will come in contact with the pin e, and force it and the arm a to the left' till the plate a cramps in the groove s. If the weighted arm be inclined to the left, the, same results lwill follow, but in the opposite direction. When the arm a is thrown to the right, the lower left-hand corner of the plate a will act as a ratchet-dog` against the lower wall of the groove s, and force the wheel S round towards the left, and vice versa. The plate a und groove s f `will thus operate as a double-acting ratchet, working equally well in either direction, and having this superiority over the ordinary toothedvratchet, that its operation can be adjusted with the nicest accuracy, not being conued to the degrees marked oil by ratchet-teeth. l

With an apparatus thus constructed, it is only necessary to determine the cut which you wish to make with the saw, and set the gauge w to make that cut.. Then incline the weighted arm of lever M to the right if you wish to move the knees toward the saw, and to the left if you wish to move them away from the saw. Every time the lever L is now moved in one direction through the distan'ce between the pin p *and gauge w, the knees and log will be advanced exactly the distance required for a new cut; but when the lever L is moved back to position again, no effect is'produced upon the log, and this action may be instantaneously reversed by changing the position of the weighted lever M, as above described. It is evident that thc lever L may easily be operated by the carriage itself, as it reaches the extremity of its movement in either direction, or it may be operated by hand. A A

Having thus described my invention, what I claim as new, and desire to secure by LettersvPatent, is

1. The combination of the knees C C, tables T, and rod R, substantially as and for the purpose described.

2. The combination of the reversing-lever L, having the pin Z, arm a', and weighted levenM, with the grooved -wheel S attached to the shaft S, all being constructed and arranged substantially as and for the purposespeciied. f t

' THOS. C. BALL.v

" Witnesses:

A. S. CAMPBELL, WILL. F. GRIFFIN; 

